Question: $ { \left[\begin{array}{rr}{2} & {4} \\ {-1} & {0} \\ {-2} & {1}\end{array}\right]-\left[\begin{array}{rr}{2} & {2} \\ {4} & {-2} \\ {2} & {-2}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{2}-{2} & {4}-{2} \\ {-1}-{4} & {0}-{-2} \\ {-2}-{2} & {1}-{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {2} \\ {-5} & {2} \\ {-4} & {3}\end{array}\right]}$